<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>画图形</title>

    <style>
      .circle {
        width: 100px;
        height: 200px;
        background: green;
        border-radius: 50%;
      }

      .triangle {
        width: 0;
        height: 0;
        border: 100px solid transparent;
        border-bottom-color: green;
      }

      .sector {
        width: 0;
        height: 0;
        border: 100px solid transparent;
        border-bottom-color: green;
        border-radius: 50%;
      }

      .trapezoid {
        width: 70px;
        height: 0;
        border: 100px solid transparent;
        border-bottom-color: green;
      }
    </style>
  </head>
  <body>
    <div class="circle"></div>
    <div class="triangle"></div>
    <div class="sector"></div>
    <div class="trapezoid"></div>
  </body>
</html>
